The invention is directed to process for embossing polymeric substrates by using a composite sheet structure that is used as a blanket in a dielectric press.
Dielectric presses are used to emboss designs on laminates such as a thick thermoplastic urethane foam laminated to a cotton scrim fabric on one side and a short napped synthetic velour fabric on the other side. These laminates are used as upholstery in automobiles and trucks. A blanket is positioned between the platens of the press and the substrate being embossed to prevent the substrate from sticking to the platens and prevent shorting of the platens of the press.
Blankets of silicone rubber layer adhered to a fiberglass cloth and blankets of fluorocarbon polymer layer adhered to a polyamide fabric have been used but these blankets act as a thermal barrier and do no heat up sufficiently during the embossing process and prevent development of sufficient heat in the laminate to emboss and seal a pattern into the laminate. A blanket is needed that has good electrical insulating properties and that will heat up internally during a dielectric embossing process and allow the substrate to be embossed.